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UNITED STATES PATENT QFFIGE.

OYPRIEN MARIE TESSIE DU MOTAY AND CHARLES RAPHAEL MAREOHAL,

OF METZ, FRANCE. 1

PHOTOGRAPHIC PROCESS.

Specification forming part of Letters Patent No. 59,520, dated November 6, 1866.

To all whom it may concern:

Be it known that we, O'YPRIEN MARIE TESSIE no MOTAY and CHARLES RAPHAEL MARE- OHAL, both of Metz, in the Empire of France, have invented certain new and Improved Processes for the Production of Photographic Images capable of being inked with fatty inks and we hereby declare the following to be a full, clear, and exact description of the same.

This invention relates to new processes for producing photographic images capable of being inked with fatty inks containing coloring-matters or vitriiiable enamels.

Its object is to combine certain chemical compositions more freely acted on by the light, having a greater affinity for fatty bodies, and adapted on this account to favor the further inking of the photographic images obtained.

These results are due, first, to the employment of salts of chromic acid, which are more acid and more complex than the protochromates and bichromates ordinarily used; sec- 0nd, to the addition to gelatinous, albuminous, or other solutions of the same group, of a body having greater reductive action upon the oxygen of the chromates; third, to the covering again by soaps of silver of gelatinous or other coats or layers containing salts of chromic acid.

These processes may be analyzed in the following manner:

First. Alkaline trichromates are mixed with solutions of gelatine and other substances of the same chemical group. There are added simultaneously either gums or acids or salts which have an affinity for oxygen, (am'dcs domygem) such as formic, gallic, pyrogallic, tartaric acids, &c., or other soluble salts formed by the same acids, or inorganic salts which have an equal affinity for oxygen, such as hyposulphites, sulphites, bisulphites, hypophosphites, phosphites, &O. The compositions thus obtained have been easily and rapidly reduced by the light, and their photographic images have reproduced, by inking, the least demitints of the original models.

Second. The bichromate of ammonia and of bichloride of mercury, (HgGl,AzH ,2UrO the bichromate of potash and of bichloride of mercury, (HgOl,Ko,2OrO the bichromate of soda and of bichloride of mercury, (HgOl,NaO,- 2OrO the trichromate of potash and of hichloride of mercury, (HgOl,Ko,3OrO and the trichromate of soda and ot bichloride of mercury (Hg0l,NaO,3OrO are employed either in a pure state or mixed with the alkaline protochromates, bichromates, and trichromates, whether combined or not with bodies having affinity for oxygen, added to gelatinous or other solutions of the same group. These compositions have given on paper, pasteboard, stone, glass, and pate cmmiqae positive images completely reduced and capable of being inked over their whole extent with fatty inks by the ordinary lithographic processes.

Third. The chromo-alkaline mercurial salts above mentioned, when dissolved and added to solutions spread in thin coats over plates of metal, zinc, brass, copper, cast or wrought iron, steel, &c., and then subjected to the action of the light, give, after being washed for a long time in water, images well reduced and very adhesive, but capable of being inked negatively; whence it follows that, in order to obtain images which can be inked positively, it is necessary to make use of positive stereotype-plates, (clicha) This result, which is the converse of that obtained with the same salts on pasteboard, wood, stone, glass, and 1a; cram'iquc, is singular and entirely new. It can be explained on the one part by the double reductive action of the light on the bichloride of mercury and the chromic acid of the chromates, and on the other part by the action of the metals decomposing, in presence of the water, the salt of mercury wherever the light has not acted.

Fourth. Coats or layers of gelatine, albumen, gum, &c., combined with any one of the salts of chromic acid above named and spread on paper, pasteboard, wood, stone, glass, pate cranm'qac, or on metal, are covered in turn, after being dried, by coatings of soaps of sil ver. In submitting them to the action of the light there are produced two images, resulting from the action of the light, by which is simultaneously effected the decomposition of the soaps of silverand the reduction of thechromates. These images, after being first washed in cold water, and then in warm water, and afterward inked by a roller, are immediately covered by fatty inks, which adhere to the names to this specification before two subplate whereverihe light has acted. scribing Witnesses.

What we claim, and desire to secure by Let- Q TESSIE DU MOTAY 1 teis Patent, 1s--- 0 R MAREGHAL The new process for the production of 'photographic images capable of being inked with Witnesses: fatty inks substantially as herein described. A. B. OETRY,

'In testimony whereof we have signed our F. F. RANDOLPH. 

